The present invention relates in general to a system for controlling the application of a solution to printing press rollers, and more particularly to an improved apparatus for applying wetting solution to the press in a controlled manner in relation to the speed of the press.
As explained in our co-pending U.S. patent application Ser. No. 870,657, filed June 2, 1986, now U.S. Pat. No. 4,649,818, the disclosure of which is incorporated herein by reference, in modern printing processes, an application of a wetting solution and ink are applied to certain rollers of the process with the ink subsequently being transferred to a printed medium, such as paper. The setting solution is applied in sufficient quantities to the rollers of the press to facilitate the printing process and aid in proper application of the ink to the printed paper.
Control of the amount of wetting solution on the inking roller is extremely important. As explained in referenced patent application Ser. No. 870,657, insufficient wetting tends to encourage the ink to migrate to improper portions of a roller and thereby be transferred to areas of the paper which are not to be printed. If an excess of wetting solution is applied, there is waste and possible wetting of the paper being printed. A smooth, even application of the wetting solution without excess is a desired result of any spray dampening system.
The spray dampening system of parent application Ser. No. 870,657 provides an exemplary application of wetting solution. However, because the spray nozzles of the system are located adjacent one another and simultaneously apply the wetting solution to the press rollers, overlap of the spraying areas of adjacent spray nozzles is practically inevitable. If the overlap is too great, an excess of dampening solution will result, with the attendant disadvantages. The purpose of this invention is therefore to overcome the possibility of unadvantageous overlap of the spray patterns of adjacent spray nozzles.